In minimally invasive surgery, anastomoses are often made using sutures of surgical thread secured by knots. Tying a knot on an organ or a vessel constitutes a difficult step during surgery since:                any slackening of sutures can lead to complications that are severe or even fatal;        tying knots while using a laparoscopic approach is technically difficult; and        the increasing number of knots required increases the duration of surgery in significant manner, and for certain operations, such as those involving vascular clamping where operating time must be kept very short, that can run the risk of leading to operative or postoperative complications.        
Proposals have been made to use clip or staple type devices, in particular in U.S. Pat. No. 5,356,459 which seeks to replace suture thread in order to avoid the need to tie knots. Nevertheless, surgeons prefer to use thread when suturing, since they have acquired automatic and habitual skills such that the sutures they make in this way are tried and tested. In addition, the reliability of clip or staple type devices has yet to be validated.